Hygrometer.



J. M. SEYMOUR, JR.

HYGROMETER.

APPLICATION FILED JAN. 26, 1915.

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WIT/NESSES:

L M. SEYMOUR, 1R.

HYGROMETER.

APPLICATION FILED JAN.26.1915.

Patented May 23, 1916.

2 SHEETS-SHEET 2- R O T N E V W.

$6M ATTORNEYS WITNESSES:

" BFCE- JAMES M. SEYMOUR, JR., OF NEWARK, NEW JERSEY.

HYGROMETER.

Specification of Letters Patent.

Patented May 23, 1916.

Application filed January 26, 1915. Serial No. 4.424;

To all whom it may concern Be it known that 1, JAMES M. SEYMOUR, J r., acitizen of the United States, residing at Newark, in the county of Essexand State of New Jersey, have invented certain new and usefulImprovements in Hygrometers; and I do hereby declare the following to bea full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and Mypresent invention therefore, has forits principal object to provide ahygrometerinstrument of simple character and construction which isprovided with a readable indicating or registering means, from which adirect and accurate reading of the percentage of humidity in theatmosphere at any time may be gained without necessity of calculatingthat percentage, as is necessary to be done with the old style wet anddry bulb thermometer-hygrometer. I

A further object of the present invention is to provide a novelconstruction'and arrangement of hygrometer instrument which willaccurately indicate or register the percentage of humidity in theatmosphere under all conditions and changes of atmospheric temperature,the instrument being so constructed that changes in temperaturedo not inany way afiect or interfere with its operations in indicatingatmospheric conditions of humidity.

Other objects of the present invention, not at this time moreparticularly enumerated, will be clearly understood from the followingdetailed description of the said invention.

With the various objects of the present invention in view, the saidinvention consists,-

primarily, in the novel hygrometer hereinafter set forth; and,furthermore, the invention consists in the novel arrangements andcombinations of the several devices and parts comprising the same, aswell as in the details of the construction of said parts, all of whichwill be more fully described in the following specification, and thenfinally embodied in the clauses of the claims which are appended to andwhich form an essential part of said specification.

i The invention is clearly illustrated in the accompanying drawings, inwhich Figure 1 is a plan or top view of a novel hygrometer, showing oneembodiment of the invention, and made according to and embodying theprinciples of the present invention. Fig. 2 is a transverse section ofthe same, said section being taken on line 2-2 in said Fig. 1, lookingin the direction of the arrow as. Fig. 3 is another transverse s'ec tionof the same, taken on line 3-3 in'said Fig. 1, also looking in thedirection of the arrow m. Fig. 4 is still another transverse section ofthe device, said section being taken on line 4- 1 in said Fig. 1, alsolooking in the direction of the arrow 00. Fig. 5 is an enlarged detailplan view of the indicating end of the hygrometer, illustrating theconstruction and operation of the novel indicating mechanism. Fig. 6 isan elevation of an indicating hygrometer, indicating a modification ofthe invention, the same still embodying, however, the principles of thepresent invention.

Similar characters of reference are employed in all of the hereinabovedescribed views, to indicate corresponding parts.

Referring now to the said drawings, the reference-character 1 indicatesa suitable base upon which the novel hygrometer may be suitably mounted,said hygrometer comprising a rod 2 and a rod 3, both of equal length andmounted to be spaced apart and parallel to each other. The said rods 2and.

3 may be of any length desired, and may be constructed of metal,hard-rubber, or in fact any material capable of contraction andexpansion.

Adjacent ends of the said parallel rods 2 and 8 may be suitably tied orclamped together, preferably by means of a transversely disposed andsuitably constructed clamping member, as 4, which rigidly connects thesaid rods and serves to hold such ends of the rods immovable, relativelyone to the other, or from moving independently of each other at suchends.

The reference-character 5 indicates a suitably formed tank or pan of alength corresponding-approximately to the length of the rod 2, said tankor pan being adapted to contain'water, or any other desired fluid.Connected with and extending transversely across said tank or pan, andextending beyond one side thereof, are a plurality of suitablyconstructed supportingbridges or spreader-members, as 6, the same beingprovided with pairs of alined grooves or channels 7 through which therespective rods 2 and 3 extend. These bridges or spreadermembers 6 notonly support the rods 2 and 3, so that the same are free to movelongitudinally thereon under the force of their expansion orcontraction, but the grooves 7 thereof tend also to keep the rodsproperly spaced and parallel, and maintain the same against lateralmovement, bending, buckling,

- or other undesired distortion, so that the suitable means.

movement caused by their expansion or contraction will be controlled anddirected or permitted only along lines longitudinal to their axes.

Suitably secured to the free or opposite ends of said rods 2 and 3, sothat the same will face each other, are toothed racks 8 and 9, andsuitably supported and rotatably mounted between said racks, and enagedon opposite sides by the teeth thereo is a pinion 10. This pinionmaybe provided with upper and lower marginal flanges, as 11 and 12, whichprevent the disengagement of the pinion from its operative relation tothe said racks 8 and 9. Connected with said pinion 10 is a forwardlyprojecting or extending needle or indicating pointer 13, the free end ofwhich is. adapted to register above and is adapted to move or'oscillatein the arc of a circle across a fixed graduated scale-member, as 1.4,the latter bein ported or secured in its fixed relation y any Thegraduations or marks 15 of said scale-member are adapted to indicatepercentages of humidity in the atmosphere.

Suitably twined or woven around the rod 2, or otherwise secured andmounted thereon, is a medium, body or strip 16 of lamp wicking, felt, orother suitable porous material, adapted by capillary attraction I totake up or soak up water or other fluid. This porous strip 16 is sowound or related to the rod 2, that while supported in contacttherewith, portions 17 of the said strip hang down therefrom, and aresubmerged in thefwater contained in the tank or pan 5 which, as has beenstated, is located beneath said rod 2. By means of this porous medium orstrip 16, the water in the tank or pan 5 is brought into contact withthe rod 2, and the evaporation of water from that portion of the porousmedium or strip, exterior of the water tank or pan 5 and in contact.with the suprod 2, chills said rod 2, so that said rod condifferentialmovement of the racks 8 and 9 connected with said rods which correspondingly rolls or rotates the pinion 10 as will be clearly evident andthereby causes a deflection oroscillation of the needle or indicatingpointer 13 from its normal or zero position, so that the same moves overthe scale-member 14 and registers with one of the graduations, andthereby immediately designates the percentage of humidity correspondingto the particular relative movement of the rods 2 and 3, and is readablein degrees without any further calculations 'on the part of the partyusing the instrument. I

It is evident, that when both rods 2 and 3 are subjected to atmospherictemperature alone, (that is when the rod 2 is not chilled,)

they will both expand and contract equally,-

each rod carrying its respective rack forward or backward, so that bothracks travel together, and thepinion 10is not rotated, the only effectupon,the needle or pointer carried thereby being to carry the sameslightly forward or backward over the scalemember 16 without deflectionor oscillation to either side of the normal or zero-point, as will beclearly understood from an inspection of the figures of the drawings.

It will thus be apparent, that changes in atmospheric temperature whenthe device is operating, (that is when the vrod 2 is chilled), providingthere are no changes in the percentage of humidity, do not aflectthe'oscillated position of the needle or indicating pointer relative to thescale-member, but a change in temperature which involves a change in thepercentage of humidity, or a change in the percentage of humiditynotinvolving a change of temperature, will be indicated upon thescale-member by a corresponding shifted position of the needle orindicating pointer.

The degree of chill produced in the rod 2 depends upon the rapidity andamount of will be the chilling effect upon the rod 2,

and the greater its contraction relative to the rod 3. It is thereforeapparent, that once the amount of fluctuation of the needleorindicating-pointer thus produced under given or known conditlons ofhumidity is ascertained and its place markedv on the invention.

scale-member by the graduations 17, subsequent readings direct from thescale-member, as indicated by the needle or indicating pointer, willever after give the percentage of humidity without the necessity of anyadditional calculations.

Referring now to Fig. 6 of the drawings, I have illustrated therein amodified construction of hygrometer, made according to and embodying theprinciples of the present In this construction I employ, in place of therods 2 and 3, a pair of mercury columns, as 18 and 19, suitably securedin fixed parallel relation to each other. The upper end of the tubescontaining the mer cury, also contain air or some suitable volatile gas,and connected in communication with the air or gas are suitablyconstructed diaphragm-members 20 and 21, which as will be evident, areadapted to expand or contract under the action or influence of the airor gas contained in said tubes. Secured to said diaphragms areconnecting rods, as 22 and .23, the respective free ends of which arepivotally connected with the butt or beam 24 of a needle orindicating-pointer 25, adapted to be deflected or oscillated withrelation to a suitable scale-member 26. As will be seen from thedrawing, that the bulb of the mercury column 18 is subjected to normalatmospheric temperature, and that the bulb of the mercury column 19 issituated adjacent to a suitable tank or pan 27 containing water, a wickor wicksof porous substance 28 being wrapped around the bulb of'the saidmercury column 19, and the ends of said wick or wicks being submerged inthe water of said tank or pan 27. Evaporation of the water from the wickor wicks surrounding the bulb of the column 19 chills the mercury columnand contracts the same, thereby reducing the compression of the air orother gas above the mercury and in consequence contracting the diaphragm21, Whereas the air or gas in the column 18 re mains compressed by theposition of the mercury column as determined by the temperature of theatmosphere. It will be apparent, that the indicating needle or pointer25 will be rocked or oscillated by the different heights attained by theconnecting-rods as determined by the differential movement of thediaphragms to which they are re- 'spectively connected, and consequentlysaid needle or pointer will indicate in degrees, by reference to saidscale-member, the percentage of humidity in the atmosphere. It

will be clearly evident, that while there are structural diflerencesbetween this modified construction of hygrometer and theconstructionpreviously described, the method and principle of operationare essentially the same, the difference residing merely in thecharacter of the expanding and contracting element, and the means fortransmitting the differential movements thereof to the needle or pointerrequired by the particular character of the expanding and contractingelements used.

I am aware therefore, that some changes ma be made in the generalarrangements an combinations of the several devices and parts, as wellas in the details of the construction of the said parts, W thoutdeparting from the scope of the present invention as set forth in theforegoing specification,

and as defined in the claims appended thereto. Hence, I do not limit myinvention to the exact arrangements and combinations of the variousdevices and'parts as herein set forth, and as illustrated in theaccompanying drawings,. nor do I confine myself to the exact details ofthe construction of the said parts.

I claim:

1. A hygrometer comprising a pair of parallel and spaced rod-memberscapable of expansion and contraction, means retaining the adjacent endsof said-rod-members at one end fixed against movement due todifferential expansion or contraction of said rod-members, the oppositeends of said rodmembers being free and capable of move- .ment due todifi'erential expansion or conthe opposite ends of said rods being freeand capable of movement due to differential expansion or contraction ofSaid rods, rack-members carried by the free ends of said rods, a pinionengaged by said rackmembers, an indicating needle connected with saidpinion, a scale-member with which said indicating needle cooperates, andmeans for chilling one of said rods by evaporation to produce adifferential expansion or contraction of said rods. v

3. A hygrometer comprising a pair of rods capable of expansion andcontraction,

a clamp-meansinterconnected with the adjacent ends of said rodsat oneend to retain said ends against movement due to differential expansionor contraction of said rods, the opposite ,ends of said rods being freeand capable of movement due to diflerential expansion or contraction ofsaid rods, rack-members carried by the free ends of vpreventing bucklingor distortion of said rods, and.

said rods, a pinion engaged by said rackmembers, an indicating needleconnected with said pinion, a scale-member with which Y difierentialexpansion or contraction of said rods, the opposite ends of said rodsbeing free and capable of movement due to differentlal expansion orcontraction of said rods, rack-members carried by the free ends of saidrods, a pinion engaged by said rackmembers, an indicating needleconnected with said pinion, a scale-member with which said indicatingneedle coiiperates,

means for supporting said rods parallel to i and spaced from each other,means for lateral movement, bending,

means for chilling one of said rods by evaporation to produce adifl'erential expans on or contractionof said rods.

5. A hygrometer comprising a pair ofrods capable of expansion andcontraction, clamping means interconnected with the adjacent ends ofsaid rods at one end to retain said ends against movement due to.diiferential-expansion or contraction of said' rods,

expansion or contraction of said rods, means for supporting said rodsparallel to and spaced from each other, means for preventing lateralmovement, bending, buckling or distortion of said rods, means forchilling one of said rods by evaporation in proportion to the moisturein the surrounding atmosphere, a mechanical device coupled with saidrods operated by the differential expanding or contracting movementsthereof for indicating the amount of such movement for the purposesspecified, and a scale with which said mechanical device operates.

6. In a hygrometer a pair of rods capable of expansion and contraction,clampmeans for retaining adjacent ends of said rods at one end againstmovement due to differential expansion and contraction of said rods, theopposite ends of said rods being free and capable of movement due todifl'erential expansion and contraction of said rods, means for chillingone of said rods by evaporation to produce a differential expansion orcontraction of said rods, and mechanism connected with the free ends ofsaid rods for the transmission of motion produced by said expansion orcontraction thereof. a

In testimony, that I claim the invention set forth above I have hereuntoset my hand this 19th day of January, 1915.

JAMES M. SEYMOUR, JR;

